The need to provide effective treatment to Spanish-speaking Latinos with PTSD is critical given the high prevalence of PTSD among Latinos in comparison to other racial/ethnic groups and the projections for dramatic demographic growth of the Latino population. The committee convened by the Institute of Medicine to assess the evidence on the efficacy of treatments for PTSD reported strong evidence supporting the efficacy of exposure therapies for the treatment of PTSD. The committee further noted that although psychotherapies may present special challenges in different ethnic/cultural groups, the evidence is mostly silent on the acceptability, efficacy, or generalizability of treatment in ethnic and cultural minorities. Eliminating health disparities for diverse cultural groups is a public health priority.One of the nation's health objectives presented in Healthy People 2010, called for eliminating disparities in mental health and mental health care for all racial/ethnic groups. Nevertheless, an evaluation conducted by the Agency for Healthcare Research and Quality in 2010 revealed that Latinos received less mental health care than other racial/ethnic groups. The report acknowledges that limited English proficiency could be a contributing factor for the gap in mental health care for Latinos. The significant impairment and the high societal costs associated with PTSD underscore the urgency of the need to make the benefits of clinical advances in the treatment of PTSD available to Latinos with limited English proficiency. The proposed study directly addresses this mental health care disparity by conducting a randomized controlled trial (RCT) to test Prolonged Exposure (PE) therapy with Spanish- speaking Latinos. In preliminary work, we translated and culturally adapted the PE therapy manual, maintaining fidelity to the original treatment, and conducted a pilot study that evidenced the feasibility and acceptability of PE for Spanish-speaking Latinos. As our next step, we propose to conduct a RCT with Spanish-speaking Latinos to determine whether PE is superior to applied relaxation in improving primary (PTSD symptoms) and secondary (functioning, health-related quality of life, and depression) outcomes. We will recruit 100 Latinos with PTSD, 18-65 years old, in primary care clinics. Assessments will be conducted at baseline, week 20, and week 28. This study has the potential to contribute to improvements in the overall well- being and quality of life of Spanish-speaking Latinos with PTSD and, by extension, likely their families as well. Misconceptions about exposure therapy can contribute to limit its adoption in clinical practices serving Latinos. If positive results are evidenced for unacculturated Latinos in Puerto Rico, characterized by dominant Latino orientation, this study would establish an evidence base for expanded research that has the potential to shift current clinical practice in mental health settings serving Latino clients by facilitating adoption of a linguistically and culturally relevan PE manual-based treatment.